Pharmaceuticals intended for oral administration are typically provided in tablet form. Tablets are swallowed whole, chewed in the mouth, or disintegrated in the oral cavity. Soft tablets that either are chewed or dissolve in the mouth are often employed in the administration of pharmaceuticals where it is impractical to provide a tablet for swallowing whole. With chewable tablets, the act of chewing helps to break up the tablet particles as the tablet disintegrates and may increase the rate of absorption by the digestive tract. Soft tablets are also advantageous where it is desirable to make a pharmaceutically active agent available topically in the mouth or throat for both local effects and/or systemic absorption. Soft tablets are also utilized to improve drug administration in pediatric and geriatric patients. Soft tablets designed to disintegrate in the mouth prior to swallowing are particularly useful for improving compliance of pediatric patients.
Generally, soft tablets are made by compaction of a blend of powdered ingredients and typically include a pharmaceutically active agent, flavoring, and/or binders. The powder blend is typically fed into the cavity of a die of a tablet press and a tablet is formed by applying pressure. Hardness of the resulting tablet is a direct function of the compaction pressure employed and the compatibility of the ingredients in the formulation. A softer tablet, having an easier bite-through, may be prepared by employing reduced compaction pressures. The resulting tablet is softer, but also more fragile, brittle, and easily chipped and disadvantageously can involve complex and costly processing steps. Examples of soft tablets designed to disintegrate in the mouth without chewing are disclosed in U.S. Pat. Nos. 5,464,632, 5,223,264, 5,178,878, 6,589,554, and 6,224,905.
Swallowable tablets have been produced utilizing a melt extrusion process, where the active ingredient is mixed with excipients, heated as a mass and extruded into preformed dies. These tablets are intended to be directly swallowed, and in some cases, have modified or sustained release properties. Examples of melt extruded tablets are disclosed in U.S. Pat. Nos. 6,387,401 and 7,022,344.
There is a need for aesthetically pleasing chewable and orally disintegrating tablets that utilize commercially efficient manufacturing methods. Orally disintegrating tablets can be prepared by compression (see, e.g., U.S. Pat. Nos. 5,223,264 and 5,178,878), but these tablets can have a high density and thus can take up to 20 to 30 seconds to fully disintegrate in the mouth. Lyophilized orally disintegrating tablets (see, e.g., U.S. Pat. Nos. 6,509,040, 5,976,577, 5,738,875, and 5,631,023) tend to be less dense and, thus, faster disintegrating. However, these tablets require a long time to make a tablet, and the process of lyophilization of the tablet formulation directly in the unit dose blister package renders a dosage form that is shaped on only one face.
The present invention relates to pharmaceutical orally disintegrating tablets (“ODTs”) having properties of rapid oral disintegration, low density, and improved robustness to handling compared to those made by a similar process (i.e., US Patent Application No. 2011/0071184) as set forth herein. The improved robustness to handling (e.g., lower friability) is also enabled by the selection of particular materials to form a low density tablet with a more resilient structure that is less susceptible to friability.